a solutiona solution is made by dissolving 3.75g of a pure nonvolatile solute in 95g of acetone. the boiling point of pure acetone was observed to be 55.95 Centigrade that,and that of the solution was 56.50 Centigrade.if the molar boiling point elevation constant(Kb)of acetone is
1.75:
To find the molar boiling point elevation constant (Kb) of acetone, we can use the equation:
ΔT = Kb * msolute * i
Where:
ΔT = boiling point elevation (difference in boiling points between the pure solvent and the solution)
Kb = molar boiling point elevation constant of the solvent (acetone in this case)
msolute = molality of the solute (moles of solute per kilogram of solvent)
i = van't Hoff factor (the number of particles formed from each molecule of solute in solution)
Here's how you can calculate the molar boiling point elevation constant:
Step 1: Calculate the molality of the solute.
Molality (m) is defined as the moles of solute (n) per kilogram of solvent (kg).
Given that 3.75g of solute is dissolved in 95g of acetone, we need to convert these quantities to moles.
Moles of solute (n) = mass of solute / molar mass of solute
= 3.75g / molar mass of solute
Step 2: Calculate the molality (m).
Molality (m) = moles of solute / mass of solvent (in kg)
= n / (mass of solvent in grams / 1000)
Given that the mass of solvent (acetone) is 95g:
Molality (m) = n / (95g / 1000)
Step 3: Calculate the boiling point elevation (ΔT).
ΔT = boiling point of the solution - boiling point of the pure solvent
= 56.50°C - 55.95°C
Step 4: Calculate the molar boiling point elevation constant (Kb).
Using the equation mentioned earlier:
Kb = ΔT / (m * i)
Substitute the values to find Kb.
Please note that the van't Hoff factor (i) depends on the type of solute and its dissociation behavior in solution. For this specific problem, we would need information about the nonvolatile solute to determine its i value.